The main change relative to [1]} is that we increase the size of the environment from 6m to 9m. A larger environment makes skill discovery more difficult, because skill discovery depends on agent discovering by chance that manipulating an object in a certain manner (such as seekers using the ramp to overcome obstacles or hiders taking the ramp out of reach of the seekers) gives them an advantage and the probability of such a chance manipulation is smaller in a larger environment. We also increase the episode length from 80 to 160 time steps to give agents more time to traverse a larger environment.
